Solutions · JEE Main previous year questions

2020 8 questions

1. Q732020 · 6 Sept 2020 · Shift 1· Numerical answer

   The elevation of boiling point of $0.10\text{ m}$ aqueous $\mathrm{CrC}{\mathrm{l}}_3\cdot \mathrm{xN}{\mathrm{H}}_3$ solution is two times that of $0.05\text{ m}$ aqueous $\mathrm{CaC}{\mathrm{l}}_2$ solution. The value of x is ______ . [Assume $100\%$ ionisation of the complex and $\mathrm{CaC}{\mathrm{l}}_2$, coordination number of Cr as 6, and that all $\mathrm{N}{\mathrm{H}}_3$ molecules are present inside the coordination sphere]

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   Answer: 5

2. Q612020 · 6 Sept 2020 · Shift 2
   
   1. A.$\text{A}<\text{C}<\text{B}$
   2. B.$\text{C}<\text{A}<\text{B}$
   3. C.$\text{B}<\text{C}<\text{A}$
   4. D.$\text{A}<\text{B}<\text{C}$
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   Answer: C

3. Q652020 · 3 Sept 2020 · Shift 1

   If the boiling point of ${\mathrm{H}}_2\mathrm{O}$ is 373 K, the boiling point of ${\mathrm{H}}_2\mathrm{S}$ will be :

   1. A.greater than 300 K but less than 373 K
   2. B.equal to 373 K
   3. C.more than 373 K
   4. D.less than 300 K
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   Answer: D

4. Q542020 · 3 Sept 2020 · Shift 2
   
   1. A.
   2. B.
   3. C.
   4. D.
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   Answer: D

5. Q632020 · 3 Sept 2020 · Shift 2
   
   1. A.only (a) is true
   2. B.(a), (b) and (c) are true
   3. C.(b) and (c) are true
   4. D.(a) and (b) are true
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   Answer: B

6. Q752020 · 9 Jan 2020 · Shift 1· Numerical answer

   How much amount of $\mathrm{NaCl}$ should be added to 600 g of water ($\rho =1.00\text{ g/mL}$) to decrease the freezing point of water to $-0.2{}^{\circ }\mathrm{C}$ ? _______. (The freezing point depression constant for water $=2{\mathrm{K}\mathrm{kg}\mathrm{mol}}^{-1}$)

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   Answer: 1.74 to 1.76

7. Q712020 · 9 Jan 2020 · Shift 2· Numerical answer
   
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   Answer: 2.17 to 2.23

8. Q512020 · 8 Jan 2020 · Shift 2
   
   1. A.
   2. B.
   3. C.
   4. D.
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   Answer: D